Dynamo-electric machine of the homopolar type.



F. H. LORING.

DYNAMO ELECTRIC MACHINE OF THE HOMOPOLAR TYPE.

APPLICATION FILED MAR.13, 1911.

1,012,381. Patented Dec. 19, 1911.

g hdb i one) cut the lines of magnetic force in the the dead parts of the machine, so that the in the appended claims.

UNITED STATES PATEN njrn.

DYNAMIC-ELECTRIC MACHINE OF THE HOYBlIOPOLAR TYPE.

Application filed March 13,

To all whom it may concern:

Be it known that I, FREDERICK HENRY Lonrno, a citizen of the United States, residing at London, England, have invented new and useful Improvements in DynamoElect-ric Machines of the Homopolar Type, of which the following is a spec1fication.

My invention relates to the class of dynamo-electric machines indicated by the above title, 2". 6. machines in which the conductors (taken either individually, or collectively as same direction irrespective of their position in space. In machines of this class it is desirable that the armature should be of rigid construction so as to withstand high speeds; at the same time a reduction of the copper is desirable in order to effect an economy-of manufacture. To secure these benefits without undue iron losses 6. g. eddy currents in the rotating masses, due, for example, to irregularities in the polar faces, which produce variations of flux density in the rotating masses, and with good ventilation, simple machine work and straightforward methods of insulating the live from E. M, F.s may be added, the following constructional features have been worked out, and my invention accordingly consists in the arrangements and methods as set forth In the accompanying drawings, Figure 1 is a vertical central section of a homopolar dynamo constructed according to the present invention. Fig. 2 is a transverse section and Fig. 2 a face view of a corrugated rin forming part of the armature. Figs. 3 an 3 are similar views to Figs. 2 and 2 illustrating a modification. Fig. 4 is a transverse section of one of the armature conductors.

According to one example of my invention illustrated by Fig. 1, I employ a caststeel magnetic field system (a, b) with an annular gap, one exciting coil (0) suficing. A number of field coils may of coursebe used for compounding purposes, but since my invention 1s not confined to the details of the field system,'further descri tion is unnecessary. The armature whic rotates in the said annular field is built up of sheet metal rings (all of high permeability so shaped as to interlock. That is to say, they Specification of Letters Patent.

Patented Dec. 19, 11911.. 1911. Serial No. 614,160.

as to nest into each other in such a manner that when pressed together they will form a laminated ring of great strength, and, considering the diameter of the armature body thus formed, it is not of excessive weight. An example of a corrugated ring (stamping) is shown in Figs.'2 and 2 For ex ample, the rings may assume an S-, V-, U-, or a W-section, but of course the angle or curvature is not so accentuated as these letters indicate. In large units, the laminw may be built up piecemeal by adopting a well known process of electrically riveting, the shaped sections being so united as to form a ring, and the lap joints may be so arranged as to avoid air gaps, or air gaps maybe purposely arranged at suitable intervals for radial ventilation. Figs. 3 and 3* illustrate this method of forming a continuous ring out of sections, which are united without protruding rivet-heads by the following method :-The plates being of thin material, say inch thick, a considerable number of small indentations are bumped into the plates, which, on the reverse side, are dome shaped. The plates so prepared are laid together in an annular jig, or holder, and electrically welded in spots by. the heat localizedat the raised portions, when the plates are connected to a source of current and forced into intimate contact by suitable pressure The plates are preferably dished or corrugated before they are prepared for welding, although the dishing and welding may be performed in one operation. Fig. 3 shows flat. plates united in this manner, the incomplete circles representing the places where the welds have taken place.

I do not limitmyself to the use of a par ticular form of electrically-riveted system of plates, as any other system of making mechanically-sound joints may be employed, although I prefer the electrical method, since it insures a uniform thickness of material. That is to say. a pair of plates, each having a varying thickness of section owing to stretch of the metaLin shaping, may be welded in such a form as to function as a single plate of uniform thickness. The laminated ring is provided with holes for clamping bolts (6) which function as conductors. These bolts may be of drawn copper, or tough bronze, and they are anchored may be corrugated or otherwise so shapedon one side by taper heads (f) into a sysiii are collected by melt tem of insulated V- (or o her con've preferably of steel,

These rings press against. the system is held t-ogethe. or spider (2) mounted on ing compressed as much as possible lically by the bolts which are pro with nuts 7') and connectors Us), the latter in conjunction with soldered cables serving to connect the system. with a dupli- U cate one arranged to revolve in a similar field which is mechanically integral with the first-named one. The connectors (70) are made like collets so as to insure a good gripping contact. When two armatures are thus coupled together, the two spiders or disks (2') are drawn toward each. other by steel bolts (Z), their hubs'being bored tapering so as to draw against corresponding taper surfaces (m) forming a part of, or mechanically integral with, the shaft. The collecting rings may be provided with inwardly projecting blades (12), which act as fans to cause a forced air circulation through longitudinal grooves (0) cut or cast in the inner pole face (72). The conductors (bolts) are preferably insulated from the lamina by strips of hard insulating material let into radial grooves, as shown by Fig, 4c, the insulating material protrudigg slightly, say from one to two millimeters, the bare intervening metal being varnished or otherwise insulated e. g. curved strips of insulating material (6 shown in section may be used. Tubular insulation may also be used or the bolts may be enameled with porcelain. The grooves however tend to obviate eddy cur-' rents in the bolts. The bearings (q) are supported by the field system, and a large number of collecting; brushes together with copper cables or rods are provided fortaking 01f the currents, the circuits being arranged so that the E. M. FPS are added. The inner and outer polar faces of the armature are ground to insure great truth, and the bolts are so disposed as to in uref'a perfoot balance. Very small air gaps are providepl and a comparatively intense magnetic field obtained. The machine may be separately excited, and the magnetizing coil is held against a faced portion (r) of the fieldsystem on one side to assist the conduction of the heat therefrom into the steel parts which have a larger radiating surface. The opposite side of the coil is exposed to the air currents induced, by the above mentioned fan-blades (see arrows). The field system is provided with radial openings (.9) so that the collecting brushes and connecting bars or cables can be introduced. The openings also facilitate ventilation. The hearings or the parts adjacent thereto are provided with air ducts (t) which communicate with the annular space between L116 the inn pole, this in turn on with the air ducts (0) in the im c In order that the sep raoe which are corrugated shaped, ample, shall lie in hard con not both at the inner and outer per 7 that eaca stamping general thickness. This plished in several ways. T A dished when red-hot by spe i tools, whim insure a uniform cross-section, or raises. portions may be bumped on the plates, which will correct the inequalities due to stretch, e. g. as when they shaped in the cold. Still another method consists in so called electrically riveting together a pair of plates so that the riveted portions will be of uniform thickness and thus tend to equalize the variations due to the dishing operations.

The generator armature may be arranged to be driven vertically instead of horizontally as here shown.

1. A homopolar dynamo-electric machine comprising a field-magnet, annular polar surfaces in a magnetic circuit of said magnet, an annular armature movable between said polar surfaces and consisting of a plurality of laminae formed of material of suitable magnetic permeability, which laminae have recesses on one side and corresponding projections on the other side and are nested one into the other, a rotary shaft, a supporting frame on said shaft, conducting bolts connecting said laminae and said supportingframe and extending transversely to the direction of the magnetic flux, and means for collecting the current generated in said bolts.

2. A homopolar dynamo-electric machine comprising a field-magnet, annular polar surfaces in a magnetic circuit of said magnet, an annular armature movable between said polar surfaces and consisting of a plurality of laminae formed of material of suitable magnetic permeability, which laminm have recesses on one side and corresponding projections on the other side and are nested one in the other, a supporting frame on said shaft, conducting bolts connecting said laminae and said supporting frame and extending transversely to the direction of the magnetic flux, collecting rings connected to the ends of said bolts and pressing against said laminae, and brushes bearing against said rings.

3. A homopolar dynamo-electric machine comprising a field-magnet, annular polar surfaces in a magnetic circuit of said magnet, an annular armature movable between said polar surfaces and consisting of aplurality of laminae formed of material a rotary shaft,

aoraeer of suitable magnetic permeability, which laminae have recesses .on one side and corresponding projections on the other side and in said bolts.

l. A homopolar dynamo-electric machine comprising a field-magnet, annular polar surfaces in a magnetic circuit of said magnet, an annular armature movable between said polar surfaces and consisting of a plurality of laminae formed of material of suitable magnetic permeability, which laminae have recesses on one side and corresponding projections on the other side and are nested one in the other, a rotary shaft, a supporting frame on said shaft, conducting bolts connecting said laminae and said supporting frame and extending transversely to the direction of the magnetic flux, collecting rings connected to the ends of said bolts and pressing against said laminae, inwardly-projecting fan-blades on said 001- lecting rings, and brushes bearing against said rings.

5. A homopolar dynamo-electrlc machine comprising a field-magnet having two magnetic circuits, annular polar surfaces in said magnetic circuits, two annular armatures movable between said polar surfaces and consisting of a plurality of laminae formed .of material of suitable magnetic permeability, which laminae have recesses on one side and corresponding projections on the other side and are nested one in the other, a rotary shaft, a supportingframe which is adapted to engage with one end of each annular armature and is mounted on said shaft, conducting bolts mechanically connecting said laminae and said supporting frame, which bolts are electrically connected together at their inner ends and extend transversely to the direction of the magnetic flux, collecting rings electrically and mechanically connected to the outer ends of said boltsand brushes bearing against said rings.

FREDERICK HENRY LORING.

Witnesses:

JOHN THOMAS KNOWLES, THOMAS ALFRED BAILEY. 

